Examine source code of OledFox

{
  "manifest_version": 3,
  "version": "2.4",
  "name": "OledFox",
  "description": "Redjards oled version of the Dark Fox theme.",
  "theme": {
    "images": {
      "theme_frame": "darkfox.png"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#FFFFFF",
      "toolbar": "#00000000",
      "toolbar_text": "#FFFFFF",
      "toolbar_field": "#000000A0",
      "toolbar_field_text": "#ffffffc0",
      "tab_line": "#FFFFFF80",
      "popup": "#000000",
      "popup_text": "#FFFFFF",
      "tab_loading": "#FFFFFF"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "oledfox.theme.firefox@redjard.org"
    }
  }
}